CN113272078A - Air purging unit - Google Patents

Abstract

Provided is an air purge unit capable of removing dirt on a lens surface of a photosensor with a small air supply amount. The air purge unit 2 includes: a frame body 30; an air supply port 31 for supplying air into the housing 30; and a plurality of air blowing ports 32 arranged on the side wall of the housing 30 for blowing air to the lens surface 11a of the photoelectric sensor 1.

Description

Air purging unit

Technical Field

The invention relates to an air purging unit (air purge unit).

Background

Conventionally, there are photoelectric sensors that detect the presence or absence of a workpiece and the like using light. The photoelectric sensor emits detection light toward a workpiece, for example, and then analyzes the light transmitted through or reflected from the workpiece, thereby performing various detections (for example, patent document 1).

Photoelectric sensors are sometimes provided in environments where machining is performed. In such an environment, dirt such as dust or processing oil may adhere to the lens surface of the photosensor through which light passes, and the amount of light passing through the lens surface may decrease. Thus, there is a possibility that the workpiece cannot be appropriately detected. Therefore, the following method is employed: an air purge unit for blowing air to the lens surface is attached to the photoelectric sensor to prevent dirt from adhering to the lens surface. For example, as shown in fig. 8, anair purge unit 2 provided with anelongated air outlet 60 along thelens surface 11a may be attached to thephotoelectric sensor 1 to remove dirt on thelens surface 11 a.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-077050

Disclosure of Invention

Problems to be solved by the invention

However, when dirt that is difficult to fall adheres to the lens surface, air having a large flow velocity must be blown out from the air outlet. At this time, a large amount of air must be supplied to the air purge unit, thereby causing a problem of an increase in electric power for supplying the air, or the like.

Therefore, an object of the present invention is to provide an air purge unit capable of removing dirt on a lens surface of a photosensor with a small air supply amount.

Means for solving the problems

An air purge unit of an embodiment of the present invention includes: a frame body; an air supply port for supplying air to the inside of the housing; and a plurality of air blowing ports arranged on the side wall of the frame body for blowing air to the lens surface of the photoelectric sensor.

According to this aspect, the plurality of air outlets are arranged in a row on the side wall of the air purge unit. Therefore, the air can be blown over a wide range of the lens surface through the plurality of air outlet ports while reducing the size of each air outlet port. As the size of the air outlet is reduced, the flow velocity of the air blown out from each air outlet of the air purge unit is increased as compared with the conventional air purge unit in which a single large air outlet is provided. That is, the air purge unit of the present invention can remove dirt on the lens surface of the photosensor with a small air supply amount.

In the above aspect, the plurality of air outlets may be arranged linearly.

In the above aspect, the plurality of air outlet ports may be provided along the extending direction of the lens surface.

According to this aspect, the air blown out from the air blowing port of the air purge unit is easily blown to the lens surface, and dirt adhering to the lens surface can be efficiently removed.

In the above aspect, the plurality of air outlets may be circular holes.

In the above aspect, the corner portion connecting the inner surface of the plurality of air outlets and the side wall surface of the frame may be chamfered.

According to this aspect, the air is blown out so as to be widened from the air outlet. That is, since the air blown out from the air blowing port is blown over a wide range of the lens surface, the attached dirt can be removed over a wide range of the lens surface.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide an air purge unit capable of removing dirt on the lens surface of the photosensor with a small air supply amount.

Drawings

Fig. 1 is a perspective view showing an external appearance of a photosensor according to the present embodiment.

Fig. 2 is a perspective view showing an external appearance of the air purge unit according to the present embodiment.

Fig. 3 is a perspective view showing an external appearance of the air purge unit according to the present embodiment.

FIG. 4 is a view showing a state in which the air supply unit is attached to the air supply port, wherein (a) is a view showing a state before attachment, and (b) is a view showing a state after attachment.

Fig. 5 is a diagram showing a state in which the air purge unit is mounted on the photoelectric sensor.

FIG. 6 is a view showing a photoelectric sensor equipped with an air purge unit.

FIG. 7 is a sectional view of an air purge unit showing the shape of an air outlet.

FIG. 8 is a view showing a photoelectric sensor to which a conventional air purge unit is attached.

Detailed Description

Embodiments of the present invention are explained with reference to the drawings. In the drawings, the same or similar structures are denoted by the same reference numerals.

Fig. 1 is a perspective view showing an external appearance of aphotosensor 1 according to the present embodiment. First, thephotoelectric sensor 1 equipped with the air purge unit will be described with reference to fig. 1. Thephotoelectric sensor 1 detects the presence or absence of an object, the surface state of the object, or the like in a detection region using light. There are various detection methods using thephotosensor 1. For example, the following methods exist: two photosensors are prepared, onephotosensor 1 is used as a light projector for emitting light, theother photosensor 1 is used as a light receiver for receiving light, and the light received by the light receiver is analyzed to detect the light. When an object is present between the light projector and the light receiver, the amount of light received by the light receiver decreases, and therefore thephotoelectric sensor 1 analyzes the amount of decrease to detect the presence or absence of the object. Thephotosensor 1 used in the detection method is referred to as a transmission type.

As another detection method, there is a method of detecting using a photosensor in which a projector and a light receiver are integrated. This is a method of emitting light from thephotosensor 1 toward a reflective plate or an object, and receiving the reflected light by thesame photosensor 1. Thephotoelectric sensor 1 analyzes received light to detect the presence or absence of an object, a surface state, or the like. Such a photosensor that functions as both a projector and a light receiver is called a reflection type. In the present description, thereflective photosensor 1 is described as an example, but thephotosensor 1 to which the present invention is applied may be a transmissive photosensor.

Fig. 1 shows aphotoelectric sensor 1 in a state where an air purge unit is not installed. Thephotoelectric sensor 1 includes aframe 10, awindow 20, and acable 21.

Thehousing 10 houses various components such as a light projecting element and a light receiving element included in thephotoelectric sensor 1 to protect them from impact and dirt. Theframe 10 may be formed of metal, resin, or the like. Theframe 10 has afront surface 11, aback surface 12,side surfaces 13,side surfaces 14, atop surface 15, and abottom surface 16. Thefront surface 11 is a surface located on the traveling direction side of the projected light, and forms a frame surrounding thelens surface 11a through which the light is transmitted. Therear surface 12 is located opposite to thefront surface 11 with theframe 10 interposed therebetween. When thefront surface 11 is located in a forward direction and theback surface 12 is located in a rearward direction, thehousing 10 has side surfaces 13 and 14 on the left and right. The side surfaces 13 and 14 are provided so as to face each other across the inside of thehousing 10. Theframe 10 has atop surface 15 and abottom surface 16. Thetop surface 15 and thebottom surface 16 are provided so as to face each other with the inside of thehousing 10 interposed therebetween, similarly to the side surfaces 13 and 14.

Thefront surface 11 is a surface surrounding thelens surface 11a that transmits light. Thelens surface 11a is formed of a member that transmits light, and transmits light emitted from a light projecting portion (not shown) included in thephotoelectric sensor 1. Thelens surface 11a transmits light reflected from the detection object and incident on a light receiving unit (not shown) included in thephotosensor 1. Thelens surface 11a may be formed of, for example, a transparent resin or glass.

The light projecting section is a section for emitting light to the detection area, and includes a light projecting element, a light projecting lens, and the like. The light projecting element is an element that emits light, and may be, for example, a laser or a light emitting diode. The light projecting lens converts the light generated from the light projecting element into parallel light. The light projecting lens may have a part thereof exposed to the outside of thehousing 10, and for example, thelens surface 11a shown in fig. 1 may be a surface of the light projecting lens.

The light receiving unit is a unit that detects incident light, and includes a light receiving element, a light receiving lens, and the like. The light receiving element is an element for detecting light, and may be a photodiode, for example. The light receiving lens is a lens that forms an image of light incident from the detection region on the light receiving element. The light receiving lens may have a part thereof exposed to the outside of thehousing 10, and for example, alens surface 11a shown in fig. 1 may be a surface of the light receiving lens.

Theframe 10 has acommunication hole 26. Thecommunication hole 26 is a hole provided throughout the inside of thehousing 10 so as to communicate theside surface 13 and theside surface 14. In the present embodiment, thehousing 10 has twocommunication holes 26 provided in the upper and lower portions of thehousing 10, respectively. Thecommunication hole 26 is used when an air purge unit described later is connected to thephotosensor 1. Specifically, a screw is inserted from one end of thecommunication hole 26, and a tip end portion of the screw protruding from the other end is screwed into a screw hole provided in the air purge unit, thereby screwing the air purge unit to thephotoelectric sensor 1.

Thewindow 20 is provided to cover a display lamp (not shown) provided above thephotoelectric sensor 1 to protect the display lamp from impact or dirt. Preferably, thewindow 20 is formed of a transparent resin or glass, etc., so that a user can see the display lamp from the outside. The display lamp outputs the operating condition of thephotoelectric sensor 1 by emitting light. The operation state may include, for example, a power supply state or a detection state of thephotoelectric sensor 1. The display lamp may include a light emitting element such as a light emitting diode. The display lamp may be turned on when the power of thephotosensor 1 is turned on or when thephotosensor 1 detects a workpiece, for example.

Thecable 21 transmits power supplied from a power supply to thephotoelectric sensor 1. Also, thecable 21 may connect thephotosensor 1 to an amplifier unit to transmit the detection result of thephotosensor 1. At least one of the power supply and the amplifier unit may be incorporated in thephotoelectric sensor 1.

Fig. 2 and 3 are perspective views showing theair purge unit 2 attached to thephotosensor 1. Fig. 2 is a view of theair purging unit 2 from thefront surface 34 side, and fig. 3 is a view of theair purging unit 2 from therear surface 35 side. The structure of theair purge unit 2 will be described with reference to fig. 2 and 3.

The air purge means 2 is attached to theside surface 13 or theside surface 14 of thephotoelectric sensor 1, and blows air to thelens surface 11a of thephotoelectric sensor 1. Theair purge unit 2 includes ahousing 30, and anair supply port 31 and an air blow-outport 32 provided in thehousing 30.

Frame 10 includesfront surface 34, backsurface 35, side surfaces 36, side surfaces 37,top surface 38, andbottom surface 39. As shown in fig. 2, thefront surface 34 and theback surface 35 are provided so as to face each other with the inside of thehousing 10 interposed therebetween. Thefront surface 34 is located in the front direction, and therear surface 35 is located in the rear direction. Theair purge unit 2 has side surfaces 36 and 37 on the left and right. Theside surface 36 and theside surface 37 are provided so as to face each other with the inside of thehousing 10 interposed therebetween. Further, theair purge unit 2 has atop surface 38 and abottom surface 39 in the upper and lower directions. Thetop surface 38 and thebottom surface 39 are provided to face each other with the inside of thehousing 10 interposed therebetween.

In the present embodiment, the upper and lower portions of theframe 30 on the rear side are recessed inward, but the shape of theframe 30 is not limited thereto. For example, theframe 30 may have a substantially rectangular parallelepiped shape as a whole without being recessed in the upper and lower portions on the rear side.

Theair supply port 31 is a portion to which an air supply unit 50 (described later using fig. 4) for supplying air into thehousing 30 is connected. As shown in fig. 3, theair supply port 31 is provided in thetop surface 38 and theback surface 35. Further, although not shown, theair supply port 31 is also provided in thebottom surface 39. By providing theair supply ports 31 at a plurality of positions of thehousing 30 in this manner, theair supply unit 50 can be attached at an appropriate position according to the place where theair purge unit 2 is disposed. For example, when theair purge unit 2 is provided in a space having a small vertical width, theair supply unit 50 can be attached to theair supply port 31 of theback surface 35 even when theair supply unit 50 cannot be attached to theair supply port 31 of thetop surface 38.

Theair supply unit 50 connected to theair supply port 31 is a component that supplies air received from an air supply source to the inside of thehousing 30. Here, theair supply unit 50 will be described with reference to fig. 4. Fig. 4(a) is a diagram showing a state before theair supply unit 50 is attached to theair supply port 31, and fig. 4(b) is a diagram showing a state after theair supply unit 50 is attached to theair supply port 31. As shown in fig. 4(a), theair supplier 50 is formed in a cylindrical shape. Theair supplier 50 has one end (an upper end portion in fig. 4 a) connected to an air supply source and the other end (a lower end portion in fig. 4 a) connected to theair supply port 31 of theair purge unit 2. Theair supply unit 50 is detachably connected to theair supply port 31.

As shown in fig. 4(a), theair supply unit 50 has a threadedportion 51 that is tapped at a lower end portion. On the other hand, theair supply port 31 of theair purge unit 2 is threaded on its inner surface. Therefore, theair supply unit 50 is screwed to the inner surface of theair supply port 31 by thescrew portion 51, and is connected to theair supply port 31. The connection between theair supply unit 50 and theair supply port 31 may not necessarily be by screwing, and any method in which theair supply unit 50 is detachable from theair supply port 31 may be employed.

The description is continued with reference to fig. 2 and 3. Of the threeair supply ports 31 provided in thehousing 30, theair supply port 31 to which theair supply unit 50 is not attached is attached with a plug. The threeair supply ports 31 are connected to theair outlet 32 via air flow paths formed inside thehousing 30, and the threeair supply ports 31 are also connected to each other via the flow paths. Therefore, when air is supplied from any one of theair supply ports 31, the supplied air leaks from the otherair supply ports 31. Therefore, air is prevented from leaking out by fitting a plug to theair supply port 31 to which theair supply unit 50 is not connected. For example, in theair purge unit 2 shown in fig. 5, anair supply unit 50 is connected to theair supply port 31 provided in theback surface 35, and plugs 54 are attached to theair supply ports 31 provided in thetop surface 38 and thebottom surface 39.

The plurality ofair outlets 32 are arranged in a row on the side wall of thehousing 30. The air supplied from theair supply port 31 passes through the flow path inside thehousing 30 and is blown out from theair outlet 32. The air may be blown out from theair outlet 32 at all times or at fixed time intervals. In the present embodiment, theair outlet 32 is a circular hole, but the shape is not limited to this, and may be a polygonal hole such as a triangle or a quadrangle.

Screw holes 40 are provided in the side walls of theframe 30. Thescrew hole 40 is provided with a tap on an inner surface thereof for inserting a screw for mounting theair purge unit 2 to thephotoelectric sensor 1.

A method of mounting theair purge unit 2 to thephotoelectric sensor 1 will be described with reference to fig. 5. Fig. 5 is a diagram before theair purge unit 2 is mounted to thephotoelectric sensor 1. Fig. 5 shows thescrew 60 and theair purge unit 2 with thephotoelectric sensor 1 interposed therebetween. First, thescrew 60 is inserted into thecommunication hole 26 of thephotosensor 1. Thescrew 60 is formed longer than the length of thecommunication hole 26 of thephotosensor 1. Therefore, in a state where thescrew 60 is inserted into thecommunication hole 26, the tip end portion of thescrew 60 protrudes from one end of thecommunication hole 26. After thescrew 60 is inserted into thecommunication hole 26, the tip end of thescrew 60 protruding from thecommunication hole 26 is screwed into thescrew hole 40 of theair purge unit 2.

As described above, theair purge unit 2 is screwed to thephotoelectric sensor 1. Therefore, theair purge unit 2 is firmly attached to thephotosensor 1, and theair purge unit 2 can be prevented from falling off from thephotosensor 1. The method of attaching theair purge unit 2 is not limited to the screwing, and for example, thephotoelectric sensor 1 and theair purge unit 2 may be provided with a locking portion including a concave portion or a convex portion, and theair purge unit 2 may be attached via the locking portion. Also, it may be installed by adhering theair purge unit 2 to thephotoelectric sensor 1. Further, an adjustment mechanism for adjusting the position and orientation of thephotoelectric sensor 1 may be attached to theside surface 13 of thephotoelectric sensor 1 to which theair purge unit 2 is not attached.

Fig. 6 is a perspective view showing thephotoelectric sensor 1 mounted with theair purge unit 2. As shown in fig. 6, a plurality ofair blowing ports 32 are provided in a row on the side wall of theair purge unit 2. Therefore, the air can be blown over a wide range of thelens surface 11a through the plurality ofair outlet ports 32 while the size of eachair outlet port 32 is reduced. As the size of theair outlet 32 is reduced, the flow velocity of the air blown out from eachair outlet 32 of theair purge unit 2 is increased as compared with a conventional air purge unit in which a single large air outlet is provided. That is, theair purge unit 2 of the present embodiment can remove dirt on thelens surface 11a of thephotosensor 1 with a small air supply amount.

Theair outlet 32 is provided close to thelens surface 11 a. Therefore, the air blown out from theair outlet 32 keeps the momentum to reach thelens surface 11a, and the dirt adhering to thelens surface 11a can be efficiently removed.

In the present embodiment, the plurality ofair outlets 32 are arranged linearly along the extending direction of thelens surface 11 a. However, the plurality ofair outlets 32 are not necessarily provided linearly. For example, the plurality ofair outlets 32 may be arranged such thatadjacent air outlets 32 are offset from each other in the front-rear direction.

Next, the shape of theair outlet 32 will be described with reference to fig. 7. Fig. 7 is a cross-sectional view of the air blow-outport 32 of theair purge unit 2 cut in the vertical direction shown in fig. 2. Fig. 7(a) is a diagram showing an example of theair outlet 32, and fig. 7(b) is a diagram showing another example of theair outlet 32. In addition, the arrows shown in fig. 7 indicate the flow of air blown out from theair outlet 32.

First, theair outlet 32 shown in fig. 7(a) will be described. Aninner surface 44 of theair outlet 32 shown in fig. 7(a) intersects a surface (side surface 36) of theside wall 30a of thehousing 30 at acorner 45. Theinner surface 44 of theair outlet 32 and theside surface 36 intersect at a substantially right angle at acorner 45. Therefore, the air blown out from theair blowing port 32 is blown out to the outside of theair purge unit 2 without spreading as indicated by arrows.

On the other hand, acorner 46 where theinner surface 44 of theair outlet 32 and theside surface 36 meet is chamfered as shown in fig. 7 (b). In the present embodiment, thecorner 46 is chamfered by C (square chamfer), and the diameter of theair outlet 32 increases from the inside of thehousing 30 to the outside. In this way, thecorner 46 that connects theinner surface 44 of theair outlet 32 and theside surface 36 is chamfered, whereby the air that passes through theair outlet 32 is directed to widen. Therefore, the air blown out from theair outlet 32 is blown over a wide range of thelens surface 11a, and dirt can be efficiently removed.

In the present embodiment, thecorner portion 46 is chamfered by C (square chamfer), but the type of chamfer is not limited to this, and for example, chamfered by R (round chamfer) or the like may be performed.

The embodiments described above are for the convenience of understanding the present invention, and are not intended to be construed as limiting the present invention. The elements included in the embodiments, their arrangement, materials, conditions, shapes, sizes, and the like are not limited to the examples and can be appropriately changed. Also, the structures shown in different embodiments can be partially replaced or combined with each other.

[ notes ]

An air purging unit (2) comprising:

a frame (30);

an air supply port (31) for supplying air to the inside of the housing (30); and

and a plurality of air blowing ports (32) arranged on the side wall (30a) of the housing (30) and blowing the air to the lens surface (11a) of the photoelectric sensor (1).

Description of the symbols

1: photoelectric sensor

2: air purging unit

10: frame body

11: front surface

11 a: lens surface

12: back side of the panel

13: side surface

14: side surface

15: the top surface

16: bottom surface

20: window opening

21: cable with a flexible connection

26: communicating hole

30: frame body

30 a: side wall

31: air supply port

32: air outlet

34: front surface

35: back side of the panel

36: side surface

37: side surface

38: the top surface

39: bottom surface

40: screw hole

44: inner surface

45: corner part

46: corner part

50: air supply device

51: screw thread part

54: embolism

60: air outlet

Claims (5)

1. An air purging unit, comprising:

a frame body;

an air supply port for supplying air to the inside of the housing; and

and a plurality of air blowing ports arranged on a side wall of the housing, for blowing the air to a lens surface of the photoelectric sensor.

2. The air purging unit according to claim 1,

the plurality of air outlets are arranged in a linear pattern.

3. The air purging unit according to claim 1 or 2,

the plurality of air outlets are provided along the extending direction of the lens surface.

4. The air purging unit according to any one of claims 1 to 3,

the plurality of air outlet ports are circular holes.

5. The air purging unit according to any one of claims 1 to 4,

corners connecting inner surfaces of the plurality of air outlets and side wall surfaces of the frame body are chamfered.

Images